Pacific Whale Foundation helps document a record-breaking whale voyage

The Pacific Whale Foundation has helped publish a new study that documents the longest individual humpback whale movements ever recorded—including one animal tracked crossing more than 8,700 miles between Brazil and Australia over 22 years.

The foundation was a co-lead organization on the research, published May 20 in the journal Royal Society Open Science. The foundation’s Cristina Castro and Stephanie Stack of Griffith University in Australia led the international team, which included researchers from Brazil, Ecuador and the United States.

The study identified two humpback whales that traveled between breeding grounds in eastern Australia and Brazil — on opposite sides of the planet, separated by two oceans. One whale was first photographed off the coast of Bahia, Brazil, in 2003 and then spotted in Hervey Bay, Australia, in September 2025, a straight-line distance of approximately 9,400 miles. The other made the reverse crossing, documented between Queensland and São Paulo over a 12-year span. Both journeys surpass the previous record for the greatest distance ever confirmed between sightings of the same individual humpback whale.

To identify the animals, researchers compared 19,283 photographs of humpback tail flukes — each as unique as a fingerprint — collected between 1984 and 2025 from eastern Australia and Latin America. The images were processed through an automated recognition algorithm and then verified manually. Out of nearly 20,000 individual whales in the database, only two had made the crossing, representing just 0.01% of identified animals.

Researchers say the rare crossings likely occur when whales from different breeding populations encounter one another on shared Antarctic feeding grounds and then follow a different migration route home. Climate-driven changes in the Southern Ocean, including shifts in sea ice and krill distribution, may make such journeys more frequent over time. Despite their rarity, these inter-ocean movements help maintain genetic diversity across whale populations.

Much of the photo data was gathered through Happywhale, a global platform that aggregates whale identification records from professional researchers and citizen scientists alike.

“This kind of research highlights the value of citizen science,” Castro said. “Every photo contributes to our understanding of whale biology and, in this case, helped uncover one of the most extreme movements ever recorded.”

The study is the result of decades of fieldwork and data sharing across multiple organisations spanning the Southern Hemisphere. Contributing groups include the Pacific Whale Foundation, Instituto Baleia Jubarte, Projeto Baleia à Vista, the Laboratory of Bioacoustics at the Universidade Federal do Rio Grande do Norte, Happywhale, and Griffith University. The Happywhale platform, which aggregates photo-identification records from researchers and members of the public worldwide, was central to making the cross-catalogue comparisons possible. 

“Discoveries like this are only possible because of investment into long-term multi-decadal research programs and international collaboration,” Stack said. “These whales were photographed decades apart, by different people, in different parts of the world, and yet we can connect their journey.”

Founded in 1980, Pacific Whale Foundation conducts research, education and conservation programs with its base of operations on Maui.